After girls enter puberty, with the development of mammary glands, the lines of breasts become more and more obvious. Breast is one of the most remarkable secondary sexual characteristics of girls, and its normal development will directly affect the beauty of women's body. Breast is the organ with the longest development time for girls. Generally speaking, it takes 8-9 years for Chinese girls to develop their breasts. Mature mammary glands are mature, adipose connective tissue is increased, the boundary between areola and nipple is clear, and areola becomes a part of breast. The whole breast is hemispherical and plump. In the process of breast development, there are great differences among individuals. Some may develop earlier and faster, while others may develop later and slower. There is a certain relationship between breast development and heredity. In addition, it also has a certain relationship with people's body shape. Therefore, there is no absolute standard for the size of breasts, as long as they are within the normal range. But if after puberty, the breasts are still undeveloped, the chest is flat, and the appearance is still the same as that of children, it is not normal. You should go to a specialist hospital for examination. On the contrary, early breast development (grade one or two in primary school), accompanied by menstrual cramps, may be the performance of precocious puberty. Check and treat in time. After puberty, the size and shape of the two breasts should be basically symmetrical. If there are obvious differences, it will not only affect the chest fitness, but also cause a certain psychological burden. If necessary, you can go to a special hospital for plastic surgery or wear a plastic bra to make up for its shortcomings. The symmetry difference is not too big, and there is no obvious abnormality in the development of other organs. Under the guidance of a doctor, active physical therapy or self-massage can also achieve certain results. In addition to genetic factors, breast development is also related to physique, nutrition and health. Generally speaking, women who are well-developed, like sports and pay attention to nutrition have better breast development, and vice versa. If you want to keep your chest fit, shape your body beauty and establish a beautiful image of modern women, you should pay attention to and cultivate it from the following aspects.

1. Pay attention to balanced and comprehensive nutrition. Breast is an important gland in human body. If the required nutrients, especially protein and fat, are insufficient, it will affect the development, and even adversely affect the milk production and secretion in the future.

2, pay attention to develop a good posture, develop the correct posture of sitting, standing and walking from an early age, keep the upper body upright, don't hunch back, don't hunch back, and develop the habit of holding out the chest, which is extremely important to ensure the normal development of the chest and avoid bending over and improper behavior.

3, be careful not to corset the chest, especially those who have an early chest development and are more introverted. These girls will feel shy and embarrassed in the face of breast enhancement, so they use corsets or tight underwear to cover it up. They mistakenly believe that if they tie it tightly, it will not develop much. As everyone knows, this will not only limit the increase of breasts, but also easily affect the normal development of breasts, and also easily lead to some diseases and adverse consequences. The sternum of teenagers develops a little later than other parts, and the sternal joint is gradually completed at the age of 20. The developing sternum, ribs and long-term tightening tights and corsets will hinder the normal development of the chest, and the cardiopulmonary and respiratory functions of the chest will be affected. Medical data show that people with long-term chest constraints have worse chest development than those without chest constraints of the same age. The lung capacity is also much lower. Long-term abdominal restraint will also make the nipple sag, making it difficult for the baby to feed after adulthood, which is called "blind nipple" by the people. On the other hand, long-term compression of the breast will lead to breast hypoplasia, affect milk secretion and easily get mastitis. In addition, if mature girls have flat breasts, they will also affect their youthful appearance.

4, pay attention to do more chest exercises, such as chest expansion, push-ups, technical stretching, aerobics, swimming and other sports, can promote the development of chest muscles. Well-developed breasts (bones and muscles) and well-developed breasts can better reflect the beauty of curves. Before going to bed or after getting up, it is best to do several stretching exercises, expand your chest and take a deep breath, so that your chest can fully develop and persevere, which will achieve unexpected results. It is important to insist that self-massage also plays an auxiliary role in breast development.

5, pay attention to protect the breast, breast is composed of 15──20 mammary glands, each breast has a catheter leading to the nipple, so as to secrete milk in the future. When the breast is squeezed by external force, it is easy to form inflammation, that is, mastitis (called "breast sore" and "breast carbuncle" in folk). Therefore, we should pay attention to the protection of the breasts at ordinary times, and don't squeeze, collide or sleep on your stomach, so as not to oppress the breasts. Wear a proper bra during exercise to avoid collision and prevent inflammation or hyperplasia.